Re: Displaying an NSArray of NSArray's in a Table view

FROM : Jonathan Jackel
DATE : Sun Dec 12 18:17:56 2004

You are on the right track, but I suggest reading the "Programming 
Topic" on Table Views.  That should answer your questions.

<file://localhost/Developer/ADC%20Reference%20Library/documentation/
Cocoa/Conceptual/TableView/index.html>

The value returned by your datasource should look something like

[[rows objectAtIndex:rowIndex] objectForKey:[aTableColumn identifier]];

There seems to be a typo in your code.  Don't you mean %i, not i%?

Also, an identifier can be any cocoa object (although you probably 
should limit identifiers to objects that conform to the NSCopying 
protocol so that they can be used as keys in dictionaries).  NSNumbers 
work too, but it doesn't make much difference in this context.

Jonathan

On Dec 12, 2004, at 8:36 AM, Bruce Truax wrote:

> I have implemented these methods in my datasource object.  When I have 
> used
> table views in the past I have always used bindings and I have bound 
> each
> column to the column of the table.  In this case I cannot do that 
> because
> the array is created dynamically and I do not have advance knowledge 
> of the
> columns.  It appears that I need to start with an empty table and then 
> add
> columns dynamically which I do as follows:
>
>    for (i=0;i<10;i++)
>    {
>        NSTableColumn *theColumn = [[NSTableColumn alloc] init];
>        [theColumn setIdentifier:[NSString stringWithFormat:@"i%",i]];
>        [displayArrayTable addTableColumn:theColumn];
>        [theColumn release];
>    }
> I set the identifier of each column as a string which is the same as 
> the
> column number.  This is also the key that I use in the dictionary
> representing the objects in each row. (At your suggestion that table 
> views
> are really set up to deal with arrays of dictionaries.)
>
> I then do the following:
>
>    [self setDisplayArray:[[DLDDisplayArray alloc]
> initWithCArray:outputArray
>                                            withXDimension:xSize
>                                            withYDimensiont:ySize]];
>
>    [displayArray retain];
>    [displayArrayTable setDataSource:displayArray];
>    [displayArrayTable setNeedsDisplay:YES];
>
> I end up with a table containing the correct number of columns (all 
> with the
> column header title "FIELD" but no data in the table.  I think some of 
> the
> problem is related to my column identifiers but the documentation is 
> unclear
> as to how these should be specified.  I appears that they should be the
> strings representing the keys for each column but I am not sure.
>
> Bruce
>
>
> On 12/11/04 6:51 PM, "Jonathan Jackel" <<email_removed>> 
> eloquently
> wrote:
>

>> Table views are really set up to deal with arrays of dictionaries, not
>> arrays of arrays.  Also, to understand table views you need to
>> understand table columns as well.  I would spend some time with the
>> NSTableView and NSTableColumn docs (NSArray and NSMutableArray docs,
>> too).
>>
>> I imagine that there is some clever way of making this work with
>> bindings, but I don't know it.  I would use a data source and five
>> lines of code.
>>
>> In the table datasource, implement this (written in Mail):
>>
>> - (int)numberOfRowsInTableView:(NSTableView *)aTableView
>> {
>>    return [rows count];
>> }
>>
>> - (id)tableView:(NSTableView *)aTableView
>>    objectValueForTableColumn:(NSTableColumn *)aTableColumn
>>    row:(int)rowIndex
>> {
>> int columnIndex = [[aTableView tableColumns]
>> indexOfObject:aTableColumn];
>>        return [[rows objectAtIndex:rowIndex]
>> objectAtIndex:columnIndex];
>> }
>>
>> -  (void)tableView:(NSTableView *)aTableView
>>    setObjectValue:anObject
>>    forTableColumn:(NSTableColumn *)aTableColumn
>>    row:(int)rowIndex
>> {
>> int columnIndex = [[aTableView tableColumns]
>> indexOfObject:aTableColumn];
>> [[rows objectAtIndex:rowIndex] replaceObjectAtIndex:columnIndex
>> withObject:anObject];
>> }
>>
>> Jonathan
>>
>> On Dec 10, 2004, at 8:57 PM, Bruce Truax wrote:
>>

>>> As some of you have seen from an earlier post, I have taken a two
>>> dimensional C array of floats and created an NSMutableArray (rows) of
>>> NSMutableArrays (columns) of NSNumbers which I created from the C
>>> array of
>>> floats.  It seems that this should be easy to display in a table view
>>> but it
>>> is not obvious how to do this.  Binding the content array of the 
>>> table
>>> view
>>> to the NSMutableArray does not cause the display, neither does 
>>> setting
>>> the
>>> data source.
>>>
>>> Suggestions are appreciated.
>>>
>>> Bruce
>>> --

>